GCD常用函数

最新推荐文章于 2024-12-27 13:06:05 发布

SpencerAn

最新推荐文章于 2024-12-27 13:06:05 发布

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分类专栏： GCD

本文链接：https://blog.csdn.net/anspencer/article/details/56110132

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1. ios延迟执行的几种方法

[selfperformSelector:@selector(方法)withObject:nilafterDelay:2.0];

[NSTimerscheduledTimerWithTimeInterval:2.0target:selfselector:@selector(方法)userInfo:nilrepeats:NO];

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)),dispatch_get_main_queue(), ^{

NSLog(@"");

});

gcd方式的优势：

可以控制在xx时间之后在哪个线程中执行。

2. GCD一次性代码：在程序的运行过程中只被执行一次

-(void)once
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        NSLog(@"一次性代码")
    });
}

3.栅栏函数

注意：栅栏函数不能使用全局并发队列

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController


-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    
    
    dispatch_queue_t queue=dispatch_queue_create("test", DISPATCH_QUEUE_CONCURRENT);
    dispatch_async(queue, ^{
        
        NSLog(@"test一，当前线程是%@",[NSThread currentThread]);
    });
    
    
    dispatch_async(queue, ^{
        
        NSLog(@"test二，当前线程是%@",[NSThread currentThread]);
    });
    
    dispatch_barrier_async(queue, ^{
        NSLog(@"我是栅栏++++++++++++++++++++++++++++++++++++++++++++");
    });
    
    dispatch_async(queue, ^{
        
        NSLog(@"test三，当前线程是%@",[NSThread currentThread]);
    });
    
}

@end

4.GCD快速迭代

一共要传3个参数：

参数1；次数

参数2：队列（只能传并发队列，主队列会发生死锁串行队列无作用）

参数3：索引 index

转移文件夹内容代码

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self moveFileGCD];
}

-(void)moveFile
{
    //1.获取文件夹地址
    NSString *from =@"文件夹地址";
    NSString *to=@"文件夹地址";
    
    
    //获取目录下面的文件的路径
    NSArray *subpaths = [[NSFileManager defaultManager]subpathsAtPath:from];
    
    NSLog(@"内容：%@",subpaths);
    
    //遍历所有的文件
    NSInteger count=subpaths.count;
    
    
    for (NSInteger i=0; i<count ; i++) {
        //拼接文件的全路径
        NSString *fullPath=[from stringByAppendingPathComponent:subpaths[i]];
        NSString *toFullPath=[to stringByAppendingPathComponent:subpaths[i]];
        
        
        [[NSFileManager defaultManager]moveItemAtPath:fullPath toPath:toFullPath error:nil];
        
        NSLog(@"全路径：%@------------------全路径：%@-----------%@",fullPath,toFullPath,[NSThread currentThread]);
        
    }
}

-(void)moveFileGCD
{
    //1.获取文件夹地址
    NSString *from =@"文件夹地址";
    NSString *to=@"文件夹地址";
    
    
    //获取目录下面的文件的路径
    NSArray *subpaths = [[NSFileManager defaultManager]subpathsAtPath:from];
    
    NSLog(@"内容：%@",subpaths);
    NSInteger count=subpaths.count;
    //创建并发队列
    dispatch_queue_t quque=dispatch_queue_create("queue", DISPATCH_QUEUE_CONCURRENT);
    dispatch_apply(count, quque, ^(size_t i) {
        //拼接文件的全路径
        NSString *fullPath=[from stringByAppendingPathComponent:subpaths[i]];
        NSString *toFullPath=[to stringByAppendingPathComponent:subpaths[i]];
        
        
        [[NSFileManager defaultManager]moveItemAtPath:fullPath toPath:toFullPath error:nil];
        
        NSLog(@"全路径：%@------------------全路径：%@-----------%@",fullPath,toFullPath,[NSThread currentThread]);
        
    });
}

@end